Sealing compositions which contain acrylate copolymer dispersions and organoaminosilanes, together with highly dispersed silicic acids, which have an improved intrinsic adhesion, resistance to water and storage stability are described in EP-A-220 841.
The known joint-sealing compositions which comprise polymers of ethylenically unsaturated monomers in the form of aqueous dispersions as binders have the serious disadvantage that their setting ability is extremely slow at low temperatures. At temperatures of about 0.degree. C., vulcanization is delayed over a period of many hours. At minus temperatures, below 0.degree. C., it can often take days until the paste crosslinks to a state which gives the matrix inner strength to the extent that it can also be subjected to load. These product properties restrict the use of this class of substance for many practical applications. Precisely in regions where low temperatures prevail for prolonged periods of time, these sealing compositions are exposed to an increased risk. If the sealing compositions have not set sufficiently and in the meantime they are exposed, for example, to rain, these products can be washed out by the rain, that is, the sealing composition dissolves and the binder and all the other materials are washed away.
At low temperatures, the evaporation of water is greatly reduced. In addition, if the relative atmospheric humidity of the environment is relatively high, the rate of crosslinking is, moreover, further delayed.
Therefore, it is an object of the present invention to provide sealing compositions which contain polymer dispersions obtained from ethylenically unsaturated monomers. Another object of the present invention is to provide polymer dispersions which set rapidly, especially at low temperatures. A further object of the present invention is to provide polymer dispersions which are resistant to rain a short time after application and adhere firmly to the substrate.